Community Beliefs Regarding Dioxin Exposure Pathways

Edith Parker, Dr.P.H. University of Iowa NIEHS Grant R01ES016306

A study, partially funded by the NIEHS, found that residents of communities with known dioxin contamination made incorrect assumptions about how and where they might be exposed to dioxins. Despite the fact that dioxins aggregate, rather than disperse, in water 79.3 percent of survey respondents incorrectly believed that dioxins could be found in river water even after the removal of all soil and sediment. The study shows the importance of clearly communicating the specific exposure pathways of contaminants.

The researchers mailed surveys to 904 Michigan residents who lived in communities where dioxin contamination had occurred. Just over 70 percent of the respondents believed that well water could have elevated levels of dioxins, and 30.8 percent believed that elevated levels of dioxins could be found in the city water supply. Residents who did not trust the government or were personally concerned about dioxins were more likely to believe that drinking and touching water were still significant routes of dioxin exposure.

The researchers point out that the residents have repeatedly heard that industrial discharge into the river was the source of most of the present dioxin contamination and that the river is thus contaminated. The researchers were not surprised that the residents concluded that the river water is tainted even though the dioxins are likely to quickly bind to particles in water and accumulate in sediment at the bottom and banks of the river. For future communication with residents, the researchers suggest that an analogy such as dioxins are more like oil than water, might help mitigate concerns about drinking water and contact with river water. Analogies could also help increase awareness of potential problems involved with disturbing riverbank soil or river sediment as well as eating bottom-feeding fish.